Functional Electrical Stimulation
Functional Electrical Stimulation (FES) is primarily used in the rehabilitation of motor functions and sensory functions. It is also used to restore bladder, bowel and respiratory functions. FES is a treatment where either the affected muscle is directly activated by an electric shock or the associated nerves are activated by an electric shock, which consequently moves the muscle connected to the nerves. It may be used to improve muscle strength following injury or disuse. By exercising the affected muscle groups, you increase the blood flow, which can prevent or reverse a decline in function. FES may also be used as part of a treatment to regain motor function by assisting or replacing a person’s voluntary ability.1 Additionally, research is currently underway to assess the possible benefits FES might have for neuromuscular retraining.2
FES is a system that consists of a stimulator that sends out electrical impulses and a set of electrodes that administer the impulses to the muscle or nerve. The electrodes are typically placed on the skin, close to the affected limb.
However, systems that use invasive, implanted electrodes are also in use. In the case of the non-invasive systems, electrodes are placed on the skin and then connected to a stimulator (both wired and wireless systems exist) worn around the waist, arm or leg.3 Surface systems enjoy the benefits of being non-invasive and relatively inexpensive. However, difficulties may arise with this kind of system because repeated placement of the electrodes in the appropriate locations requires skill and patience. Furthermore, as the electricity must pass through pain receptors in the skin, the subject could experience some pain. It might also be hard to activate deep muscles and to achieve isolated contractions. Additionally, the amount of wires and devices that one must wear can feel bulky and impractical.4
Invasive systems come in two kinds. The less invasive ‘percutaneous’ system involves implanting the electrodes by inserting them through the skin into the muscles using a hypodermic needle. The electrode leads exit the skin and are, like the surface system, connected to external stimulation equipment. As the leads must pass through the skin, they are very fine and therefore not as durable as other leads. The more invasive ‘fully-implanted’ system involves implanting the stimulator in the body, eliminating the need for outside wiring. As the leads do not need to go through the skin, they can be more robust and therefore more durable. The stimulator is typically implanted in the chest or abdomen.5
- Possible benefits of Functional Electrical Stimulation for stroke
- Arguments against using Functional Electrical Stimulation for stroke
- Case histories
- Notes and references
Aviva Cohen is the author and CEO of Neuro Hero